R Econ Visual Library

# Install and load packages ---------------
packages <- c(
  "tidyverse",
  "haven",
  "pBrackets",
  "rdd",
  "splines"
)

# Change to install = TRUE to install the required packages
pacman::p_load(packages, character.only = TRUE, install = FALSE)

# Load an example dataset ---------------
# https://openknowledge.worldbank.org/handle/10986/25030
data <- read_dta("https://github.com/worldbank/r-econ-visual-library/raw/master/Library/Data/evaluation.dta")

cutoff <- 58

data <- data %>%
  filter(treatment_locality == 1) %>%
  mutate(treatment = (poverty_index <= cutoff))

p <- ggplot(data, aes(x = poverty_index, y = health_expenditures, color = treatment)) +
  geom_smooth(method = lm, formula = y ~ bs(x, 3), size = 1.0, se = FALSE)

right_y = (ggplot_build(p)$data[[1]] %>% filter(x >= cutoff) %>% arrange(x) %>% slice(1))$y
left_y = (ggplot_build(p)$data[[1]] %>% filter(x <= cutoff) %>% arrange(desc(x)) %>% slice(1))$y
diff_y = right_y - left_y

ggplot(data, aes(x = poverty_index, y = health_expenditures, color = treatment)) +
  geom_smooth(method = lm, formula = y ~ bs(x, 3), size = 1.0, se = FALSE) +
  geom_segment(
    x = cutoff + 1, xend = cutoff + 1, y = left_y, yend = right_y - 1.5, color = "black",
    linetype = 1, size = 0.02, arrow = arrow(length = unit(0.1, "cm"), ends = "both")
    ) +
  annotate("text", x = cutoff + 4, y = (right_y + left_y) / 2, label = format(round(diff_y, 2), 2)) + 
  geom_vline(xintercept = cutoff, linetype = "longdash") +
  ylim(c(0, 30)) +
  xlab("Baseline Poverty Index") +
  ylab("Health Expenditures ($)") +
  scale_color_brewer(palette = "Set2", labels = c("Not eligible", "Eligible")) +
  theme_classic() +
  theme(
    axis.text = element_text(size = 12),
    axis.title = element_text(size = 14),
    legend.title = element_blank(),
    legend.text = element_text(size = 11)
    )